Transcript No Slide Title

North Carolina
Cape Fear River Basin Plan
Final Scoping Meetings
March 6, 7, and 8, 2001
North Carolina
Cooperating Technical State
Flood Mapping Program
Overview
Purposes of the NFIP
1. Make flood insurance
available
2. Identify floodplain
areas and flood risk zones
3. Provide framework for a community’s
floodplain management ordinances
Importance of Updated Flood
Hazard Information

With up-to-date flood hazard data:

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Map users can make prudent siting,
design, and flood insurance purchase
decisions
Communities can administer sound
floodplain management programs
North Carolina’s Flood
Mapping Program

Program established to implement the
Cooperating Technical State (CTS)
Partnership with FEMA, signed
September 15, 2000

Ownership and responsibility for Flood
Insurance Rate Maps (FIRMs) delegated
to State
Organization of the CTS
Flood Mapping Program
OSBPM
John Dorman,
Program Director/Chair
CTS
Committee
NC Center for
Geographic Information
and Analysis
NC
Geodetic Survey
NC Division of
Emergency
Management
Federal Emergency
Management Agency
Rodger Durham,
Abdul Rahmani,
Program Manager
Project Manager
Mapping
Coordination
Contractor
Dewberry &
Davis LLC
State Floodplain
Mapping
Contractor
Greenhorne &
O’Mara, Inc.
State Floodplain
Mapping
Contractor
Watershed
Concepts, Inc.
Why North Carolina Is
Undertaking This Project

State’s vulnerability to hurricanes
and flooding

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14 federally declared disasters since 1989
Hurricane Floyd damages = $3.5 billion
4,117 uninsured/under-insured homes
destroyed as result of Hurricane Floyd
Accurate, up-to-date flood hazard
information crucial to protect lives
and property
Why North Carolina Is
Undertaking This Project

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Hurricane Floyd revealed flood hazard data
and map limitations
Age of North Carolina FIRMS

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
FEMA’s mapping budget is finite

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55% at least 10 years old
75% at least 5 years old
North Carolina receives only one updated
flood study for one county per year
Many counties and communities lack
resources to take on this responsibility
Benefits of North
Carolina’s CTS Program



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Current, accurate data for sound siting
and design decisions
Better floodplain management to
reduce long-term flood losses
Updated data to alert at-risk property
owners of the need for flood insurance
Faster, less expensive FIRM updates
Program Components

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Developing flood hazard studies through
community mapping needs analysis (Scoping)
Acquiring high-resolution topographic data and
accurate Digital Elevation Models (DEMs)
Conducting engineering studies
Generating countywide digital FIRMs (DFIRMs)
Designing and implementing state-of-the-art,
dynamic IT infrastructure
Supporting real-time flood forecasting and
inundation mapping capability
Digital FIRMs
+
Base
=
Topography
+
Flood Data
Digital
FIRM
Digital FIRMs

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
Digital FIRMs will be produced in a
countywide format
Will depict all flood hazard data
FIRM panels will probably be consistent
with the State land records 10,000’ by
10,000’ tiling scheme
Community Review and
Due Process

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Preliminary FIRMs provided when Cape
Fear River Basin Study is complete
90-day appeal period
Preliminary Countywide FIRMs provided
when adjacent basin studies are complete
All appeals evaluated and resolved
Final Effective FIRMs provided and made
available by the State on its Information
Management System
Additional Benefits of
the CTS Program

Digital format to allow:
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More efficient, precise flood risk
determinations
Geographic Information System (GIS)
analysis and planning
Online access 24 hours a day
DEMs will be useful for almost any
engineering or planning application
Cape Fear River Basin

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Extends from its headwaters near
Greensboro and High Point in the north
central Piedmont region of North Carolina to
the Atlantic Ocean near Wilmington and
Cape Fear
Largest river basin in North Carolina,
encompassing an area of approximately
9,300 square miles
Encompasses all or parts of 29 counties and
110 municipalities
Scoping Phase for
Cape Fear River Basin
The Scoping Phase determines:
 What areas are floodprone and need
flood hazard data developed
 Determine appropriate technical method
for developing up-to-date flood hazard
data and establish priority level
 How flood hazard data will be presented
on FIRMs
SCOPING
PRODUCTION
Step 1
Step 2
Step 3
Step 4
Step 5
Initial Research
and Community
Coordination
Initial
Scoping
Meeting
Draft
Basin
Plans
Final
Scoping
Meeting
Final Basin
Plans
Initial
Scoping
Meetings
Develop
Draft
Basin
Plans
Final
Scoping
Meetings
State
Kickoff
Meeting with
County/Local
Floodplain
Administrators
Questionnaire
State
Mapping
Needs
Assessment
NC
Scoping
Database
Generate
Initial
Scoping
Package
Finalize
Basin
Plans
FEMA
Effective
FIS & FIRM
Research
FEMA
Evaluate
Post-Floyd
Data
Process for Scoping Six River Basins
in Eastern North Carolina
Prepare
Delivery
Orders
& CTC
Mapping
Activity
Agreements
& Update
CTS
Mapping
Agreement
Analysis
and
Mapping
Step 4 — Final Scoping Meeting
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THIS IS WHERE WE ARE TODAY!
All impacted counties and communities invited
Three separate Final Scoping Meetings:
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March 6th – Haw River, NC
March 7th - Fayetteville, NC
March 8th – Burgaw, NC
Draft Cape Fear River Basin plan presented
Provides final opportunity for input
Step 5 — Final Basin Plan
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Draft Basin Plan may be revised following
the Final Scoping Meeting
Greenhorne & O’Mara, the State’s Floodplain
Mapping Contractor for the Cape Fear River
Basin, will develop proposals for the State
Cape Fear River Basin Plan will be finalized
and distributed to impacted counties and
communities
Production phase will then begin
North Carolina
Cape Fear River Basin
Meeting
QUESTIONS ON THE
SCOPING PHASE
???
Draft Cape Fear
River Basin Plan
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Summarizes scoping phase
Outlines how base maps and
topography will be acquired
Proposes engineering methods by
which each flooding source reach will
be studied
Describes the process and schedule for
completing the map production
Detailed Study — Riverine

This method requires the following:
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DEMs
Field surveys
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Channel bathymetry
Bridge/culvert opening geometry
Channel and floodplain characteristics
Detailed Hydrologic and Hydraulic Analyses
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10%, 2%, 1%, and 0.2% annual chance flood
elevations and boundaries identified (Zone AE)
Floodways delineated
Riverine Areas to be
Studied in Detail
County
Flooding Sources
Approx. Length
(miles)
Alamance
Portions of: Big Alamance Creek, Eastside Creek, Little Alamance Creek,
Michaels Branch (including Twin Lakes area), West Bank Creek
16.1
Bladen
Portions of: Cape Fear River
8.7
Brunswick
Portions of: Allen Creek, Dutchman Creek, Jackeys Creek
24.6
Chatham
Portions of: Love’s Creek, Robertson Creek
16.3
Cumberland
Portions of: Beaver Creek, Little River, Little Rockfish Creek, Rockfish Creek,
Tank Creek
50.2
Cumberland/Hoke
Portions of: Stewarts Creek
7.8
Duplin
Portions of: Rockfish Creek
2.3
Durham
Portions of: Crooked Creek, Northeast Creek and Tributaries, Northeast
Creek North Prong, Burden’s Creek and unnamed tributary, Third Fork Creek
25.9
Guilford
Portions of: Bull Run Creek, Horsepen Creek, North Buffalo Creek
25.7
Harnett
Portions of: Black River
2.1
Hoke
Portions of: Gully Branch
4.5
Riverine Areas to be
Studied in Detail
County
Flooding Sources
Approx. Length
(miles)
Lee
Portions of: Big Buffalo Creek, Little Buffalo Creek, Persimmons Creek
16.4
Moore
Portions of: Little River, McDeed’s Creek, Mill Creek, Wad’s Creek
23.0
New Hanover
Portions of: Burnt Mill Creek, Mott Creek, Prince George Creek, Smith
Creek
21.2
Onslow
Portions of: Cypress Branch, Kings Creek
7.0
Orange
Portions of: Haw Creek, Haw Creek Unnamed Tributary, Little Creek,
Booker Creek, Bolin Creek, Mill Creek
13.1
Pender
Portions of: Burgaw Creek, Long Creek, Northeast Cape Fear River,
Rileys Creek
38.5
Randolph
Portions of: Deep River, Little Polecat Creek, Muddy Creek, Muddy
Creek East Tributary, Muddy Creek West Tributary, Penwood Branch,
Polecat Creek, Sandy Creek
46.1
Rockingham
Portions of: Troublesome Creek (including Clark Lake & Reidsville Lake)
8.1
Wake
Portions of: Batchelor Branch, Beaver Creek, Kit Creek, Little Beaver
Creek, Reedy Branch, Reedy Branch Tributary, White Oak Creek
25.9
Total.
383.5
(cont’d)
Detailed Study — Coastal
This method produces the following:
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Floodplain mapping for areas along
open coast and embayments
Designations as Zones AE or VE
Coastal Areas to be
Studied in Detail
Coastal Flooding
Source
Approx. Length (miles)
County
Reach Description
Atlantic Ocean
Brunswick
Entire coastline within Brunswick County that
is located in the Cape Fear River Basin
including Oak Island, Caswell Beach, and
Bald Head Island
15.7
Atlantic Ocean
New Hanover
Entire coastline of county
30.7
Atlantic Ocean
Pender
From southern county boundary northeast
along the coastline to Topsail Beach
Total
5.4
51.8
Redelineation

This method requires the following:

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Digital Elevation Data
Effective FIS flood elevations
Proposed for all areas currently shown on
effective FIRM as Zone AE or VE and not
being restudied
Approximate Study

This method requires the following:
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Digital Elevation Data
Delineation of 1% annual chance floodplain
boundaries using approximate methods
Does not include collection/use of fieldcollected topographic data or bridge/culvert
data
Proposed for all areas currently shown on
effective FIRM as Zone A and not being
restudied in detail.
Use of Effective
Information

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This method involves no new analyses or
floodplain mapping
Effective FIS and FIRM data are digitized and
fitted to updated base map
This method is not anticipated to be used
for any communities in the Cape Fear River
Basin
Going Beyond the
Minimum

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Communities are encourgaged to
manage floodplain development
according to standards that are more
stringent than FEMA minimums.
Benefits of adopting higher standards:

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Reduced risk to lives and property, and
Lowered flood insurance premiums,
including possible Community Rating
System discounts.
Community Mapping
Options
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Community-adopted higher standards
can be supported by optional map
features shown digitally in a separate
GIS layer, or possibly printed on the
FIRM, or both.
Communities can have “customized”
flood hazard data generated for their
area through the NC Flood Mapping
Program.
Community Mapping
Options (continued)
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Customized flood hazard data options:
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1% annual chance floodplains and
elevations based on future land use
conditions (in addition to existing
conditions data),
Wider floodways based on a reduced
surcharge value (i.e., less than the 1-foot
FEMA maximum), and
Community Mapping
Options (continued)

Flood hazard data options: (continued)

Areas within a community-adopted
“freeboard contours” (i.e., areas that
would be inundated if floodwaters
reached the freeboard level)
Guidance for
Communities

The State will provide guidance to
communties on:
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Selecting higher standards options that
meet community needs,
Data the communities must provide (land
use plan, etc.),
Potential community cost sharing to cover
increased mapping costs,
Higher Standards
(continued)

State guidance: (continued)
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Model Flood Hazard Damage Prevention
ordinances that reflect enhanced
floodplain management standards, and
Outreach programs for citizens and
businesses affected by newly mapped
flood hazard areas or updated
ordinances.
Schedule for FIRM
Production
County
FIRM
Panels in
Cape Fear
River Basin
Projected
Preliminary Date
for Cape Fear
River Portion
Other Basin(s)/
Projected Preliminary Date
Alamance
85
February 2002
Roanoke River (Est. 2003)
Bladen
65
August 2002
Lumber River (August 2001)
Brunswick
81
August 2002
Lumber River (August 2001)
Caswell
3
February 2003
Roanoke River (Est. 2003)
Chatham
86
February 2002
N/A
Columbus
12
August 2002
Lumber River (August 2001)
Cumberland
109
February 2002
Lumber River (August 2001)
Duplin
68
August 2002
N/A
Durham
27
February 2002
Neuse River (February 2002)
Forsyth
7
(Est. 2003)
Yadkin River (Est. 2003)
Schedule for FIRM
Production
County
FIRM
Panels in
Cape Fear
River Basin
Projected
Preliminary Date
for Cape Fear
River Portion
Guilford
145
February 2002
Harnett
76
August 2002
N/A
Hoke
38
February 2002
Lumber River (February 2002)
Johnston
6
August 2002
Neuse River (February 2002)
Lee
47
February 2002
N/A
Montgomery
11
February 2002
Moore
61
February 2002
Lumber River (February 2002)
New
Hanover
76
August 2002
N/A
Onslow
24
August 2002
Other Basin(s)/
Projected Preliminary Date
Roanoke River (Est. 2003)
Yadkin River (Est. 2003)
Lumber River (February 2002)
Yadkin River (Est. 2003)
White Oak River (August 2001)
Neuse River (August 2002)
(cont’d)
Schedule for FIRM
Production
County
FIRM
Panels in
Cape Fear
River Basin
Projected
Preliminary Date
for Cape Fear
River Portion
Orange
36
February 2002
Pender
172
August 2002
N/A
Randolph
61
February 2002
Yadkin River (Est. 2003)
Robeson
1
February 2002
Lumber River (August 2001)
Rockingham
4
February 2002
Roanoke River (Est. 2003)
Sampson
97
August 2002
N/A
Wake
29
February 2002
Neuse River (February 2002)
Wayne
12
August 2002
Neuse River (August 2002)
Other Basin(s)/
Projected Preliminary Date
Neuse River (February 2002)
Roanoke River (Est. 2003)
(cont’d)
North Carolina
Cape Fear River Basin
Meeting
QUESTIONS ON THE
DRAFT BASIN PLAN
???